The present invention relates generally to a disposable absorbent garment, such as a diaper, and more specifically to an improved fastening system for securing the garment upon a wearer of the garment.
A variety of fasteners have been used on disposable diapers, reusable washable diapers, and waterproof garments, such as baby pants which are generally worn over the washable type of diaper. For example, U.S. Pat. No. 3,019,152 to Jones discloses baby pants having snap fasteners. U.S. Pat. No. 4,555,244 to Buell discloses a disposable diaper having reinforced holes through the diaper at the sides along the waistband. Buell provides a snap fastener which extends through the holes in the diaper to secure the diaper on a wearer. Such reusable snap fasteners inherently have a variety of small grooves and indentations which may entrap bodily wastes during wearing or changing of the diaper, leading to unsanitary conditions.
U.S. Pat. No. 2,931,361 discloses a cloth diaper having a triangular tongue portion which extends from the back waist of the diaper and which is adapted to be interwoven through vertical slots in a reinforcing piece along the front waist of the diaper. However, this interweaving is a time consuming process, and the connection is vulnerable to loosening during activity of the wearer.
A variety of refastenable adhesive tapes are used to secure a disposable absorbent garment, such as a diaper to a wearer, such as a baby. Typically, an adhesive tape is attached at each side along the back waist edge of the diaper. During the application and fitting of the diaper to the baby, typically the back waist edge is placed under a baby who is lying on his or her back. After suitably positioning the diaper under the baby, the front portion is brought up between the baby's legs and positioned along the lower front torso of the baby. The diaper is secured in place by releasing each adhesive tape from the inner side of the back waist and securing it on the outer surface along the front waist band. A suitable waist fitting is attained by varying the position of each tape along the front waist edge of the diaper.
While such adhesive tape fasteners offer convenience and safety over their traditional predecessor of cloth diapers with safety pin closures, the adhesive fasteners have several drawbacks. During the diapering of an active baby, the adhesive tapes or the areas along the front of the waist where the adhesive tapes are to attach may become coated with powders or ointments that are being applied to the baby. Such surface contaminations from ointments or powders severely degrade the quality of the adhesive closure, often rendering the diaper unusable.
While checking the diaper or during changing, the adhesive tape is susceptible to bending back upon itself and bonding with its own adhesive. Subsequent efforts to release the tape from itself often result in removing the adhesive from portions of the tape. This also degrades the tape for subsequent refitting on the baby or for disposal by rolling the waste within the diaper and using the tapes to secure the waste therein for disposal.
Disposable diapers suffer the disadvantage of liquid spreading by capillary action through the absorbent core. The liquid will migrate outwardly toward the waist and leg regions of the garment which may cause the undergarments of a wearer to become wet. Thus, a moisture barrier is desirable at the leg openings and waist. Such a moisture barrier is disclosed in U.S. Pat. No. 4,578,071 to Buell which discloses a diaper having a moisture barrier member bonded to a liquid impervious outer sheet. The outer sheet has a compacted portion with a multiplicity of spaced circles, dashes, ovals or gaps and spaces, arranged to provide a tortuous path for liquid to escape to the waist and leg openings. However, providing this tortuous moisture barrier path disadvantageously requires additional manufacturing steps and machinery, increasing the overall cost of the finished product.
Hood and loop fastener means, such as that sold under the trademark VELCRO, have been used on both disposable and reusable absorbent garments, such as diapers. Typically, VELCRO tabs extend from the back waistband and attach to matching VELCRO fasteners positioned along the front of the diaper. Such VELCRO closures have also been used in combination with D-ring belts to secure the waist portion of the garment. The D-ring belts are particularly useful in adult incontinence garments, where it is desirable to minimize bulk at the sides of the wearer.
An alternate type of VELCRO closure is disclosed in the Australian patent application No. AU-A-10962/88 to Scripps. The Scripps closure has mushroom-shaped hooks which are interconnectable with the traditional type of interwoven VELCRO loops.
The VELCRO fasteners also have disadvantages when applied to disposable diapers. A VELCRO fastener is typically a woven textile product which may be difficult and time consuming to apply to a disposable diaper, such as by sewing. The VELCRO fasteners are also more costly than adhesive fasteners, which also decreases their desirability for use on disposable garments. Additionally, the hooked portion of the VELCRO fastener may cause the wearer discomfort if the hook portion should inadvertently come in contact with the wearer's skin. Also, the woven textile backing material is often stiff and inflexible, and the edges or corners of the backing material may inadvertently rub against the wearer during use also causing discomfort. Additionally, during application of the garment the VELCRO hooks may snag other cloth in the area, such as clothing or a changing table cover, and become clogged with these foreign textile fibers. This clogging detracts from the integrity of the closure, and removing the foreign fibers is a time consuming task, which may also be painful if done by hand.
The related U.S. Pat. Nos. 4,701,170 and 4,701,176, both to Wilson, et al. and U.S. Pat. No. 4,701,179 to Kellenberger, et al., disclose another fixed position fastener system. A first pair of fastener members is attached along each side of the back waist for interconnection with a second pair of fastener members attached along each side of the front waist. Each fastener member has two fingers which extend along the surface of the diaper toward the transverse axis of the diaper. The fingers of the first pair of fasteners are adapted for interconnection with the fingers of the second pair of fasteners. To interconnect the fasteners, the garment is pulled tighter than in actual use to allow the fingers of the mating fasteners to intermesh and slide together to maintain the connection. Similarly, upon removal the garment must again be drawn tight to allow the fingers to slidably disengage. These fastener members are attached to the outer surface of the diaper with autogenous bonds, adhesives, or by stapling, riveting or sewing. The fastener members are of a plastic material having specific material properties, such as modulus of elasticity.
The fastener system of the Wilson, et al. and Kellenberger, et al. patents suffers from several disadvantages. The most notable of these disadvantages is the lack of adjustability of the fastener system to accommodate wearers of different sizes, or to allow tightening or loosening of the diaper during use. Additionally, the thickness of the interconnected fingers, adds to the bulk at the sides of the wearer. Since the fastener is of a rigid plastic it may be a source of discomfort when the wearer bends or twists at the waist. Additionally, upward leg movement at the hip joint may cause the fastener to dig into the waist and abdominal regions of the wearer further causing discomfort. Additionally, such fasteners may have sharp needle-like or knife-like edges resulting from flash, which is excess plastic that has escaped into the small space between mating plastic die halves. Such sharp edges can poke or actually cut the wearer or person applying the diaper to the wearer.
Thus, the need exists for an improved fastening system for a disposable absorbent garment, suitable for use on adults or babies or persons of ages therebetween, which is not susceptible to the above limitations and disadvantages.